# -*- coding:utf-8 -*-
class Solution:
    def rectCover(self, n):
        # write code here
        if n == 0 or n == 1 or n == 2 :
            return n
        prev1 = 2
        prev2 = 1
        for i in range(3,n+1):
            res = prev1 + prev2
            prev2 = prev1
            prev1 = res
        return res
print(Solution().rectCover(7))